The Irish National League (INL) was a nationalist political party in Ireland. It was founded on 17 October 1882 by Charles Stewart Parnell as the successor to the Irish National Land League after this was suppressed. Whereas the Land League had agitated for land reform, the National League also campaigned for self-government or Irish Home Rule, further enfranchisement and economic reforms.

The League was the main base of support for the Irish Parliamentary Party (IPP), and under Parnell's leadership, it grew quickly to over 1,000 branches throughout the island. In 1884, the League secured the support of the Roman Catholic Church in Ireland. Its secretary was Timothy Harrington who organised the Plan of Campaign in 1886. The Irish League was effectively controlled by the Parliamentary Party, which in turn was controlled by Parnell, who chaired a small group of MPs who vetted and imposed candidates on constituencies.

In December 1890 both the INL and the IPP split on the issues of Parnell's long standing family relationship with Katharine O'Shea, the earlier separated wife of a fellow MP, Capt. O'Shea, and their subsequent divorce proceedings. The majority of the League, which opposed Parnell, broke away to form the "Anti-Parnellite" Irish National Federation (INF) under John Dillon. John Redmond assumed the leadership of the minority Pro-Parnellite (INL) group who remained faithful to Parnell. Despite the split, in the 1892 general election the combined factions still retained the Irish nationalist pro-Home Rule vote and their 81 seats.

Early in 1900 the Irish National League (INL) finally merged with the United Irish League and the Irish National Federation (INF) to form a reunited Irish Parliamentary Party under Redmond's leadership returning 77 seats in the September 1900 general election, together with 5 Independent Nationalists, or Healyites, in all 82 pro-Home Rule seats.